Purifying chlorinated hydrocarbons



Patented Jam 25, 1938 I m-to STAT-ES PATEINT" oFF cE "f 1 aromas A i PURIFYING OHLORINATED HYDRO- CARBNS'- Friedrich Povenz; Rhcinfelden/Baden, and Alli-ed Rieche, Wolien, Krcis Bitter-told, Germany; 'as- -signorsto I. G. Farbenlndustrie Akticngesell- ,schaft, Frankfort-on-the-Main, Germany 3 cla ms. (01. 260-162) The present invention relates to a process for explanation of the effect of compounds, of the purifying chlorinated hydrocarbons. type of ethylene oxide in contrast with that or The chlorine derivatives of many aliphatic the known agents suchas alkalls is that the hydrocarbons, particularly those of methane, ethylene oxide dissolves as an organic compound 5 acetylene, ethylene and ethane, have a tendency in the chlorinated hydrocarbon and is thus in a 5 to decompose which is particularly noticeable as position to decdmpose n molecular pou d a development of an acid reaction during storage. bet en t e metal Sa t a d he c ro y o a Even a product which has been carefully di bon which may be present. Sultableagents of tilled possesses this tendency in a more or less 3 6 nd in q e are ethylene Oxide. and its 10 high degree. homologues and its substitution products, for in- 1 In order to limit as far as possible this propn e, epichlorhydrln, p y ethylene. O de, G erty which for practical purposes is disadvan- D y P p e e."

tageous in the chlorohydrocarbons, it, ha b The following example illustrates the invena practice to add to the materials so-called stai n: V

bilizers, the action of which depends on a t d- I Gaseous ethylene oxide is passed into the chlor- 15 ency to counteract 'a production of hydrogen inated ,hy a liquid mp of the chloride. Obviously, the efiect of these stabilizers cthyleneoxide typ s a d d t t chl rinated is limited in period, of time, the more soas the h ro a n The pro i n f the e y e; stabilizer during th ma,ny, operations which t oxide used depends on the amount of metal salt materialundergoes in practice, for example, durcontained in illuminated hydrocarbon 20 ing distillation, is more or l r v d, chlorinated hydrocarbon is then distilled in the The present invention is based on the observapresence of a small quantity of water or in a tion that the decomposition of chlorinated hydrocurrent of Steam- Alternatively the yle carbons is favoured by the presence of m n prooxide may be introduced during the distillation.

portions of the chlorides of metals, for example, Preferably there' is added an fidsol'ption e 25 iron chloride or zinc chloride. Metal chlorides instance Precipitated u a. a t vated charhave the further unpleasant property t they coal or the like, in' order to bind the finely divided act injuriously owing to catalytic effect in various metal compound J practicable reactions in hi th halogen hydrocarbbn is to remove the precipitated matter from the used as solvent, for instance, in chlorinations. 'chlol'ohydlocarbon which has been treated with 3 These metal chlorides, the formation of which is, ethylene Oxide by filtmmn if desired after addiquite unavoidable in the production of ohlori-v tion of an adsorbing agent- T p o hat d hydrocarbons, cannon be completely carbon thus purified is completely neutral and m ved by di tiil t or washing with alkali or retains its neutrality even after long standing 85 id r by absorption agents. I and even in the presence of light, air or mois- The invention consistsin aprocess of removing turn, and when a halogen hydrocarbon thus in very 'p manner these metal salts fr m treated is used as a solvent, for instance in a t t' d hydrocarbon by'treatmg the chlorination, it is found that the disadvantages t with a body of t type of t e oxide of a catalytic/ effector the metal salt has dis- 40 pref rably the presence of a Sui-9.11 proportion appeared. This elimination of metal salts from 40 of t In this manner the metal salts are chlorinated hydrocarbons is thereforea considerprecipitated in a nomvoiatile form presumably able advance in the technical applicability of the as hydroxides or basic salts which, unlike 01110: mated hydrocarbonrides, can be separated by subsequent distillation As chlorinated h a which may be of the hydrocarbon or by union with an adsorb stabilized in the manner described above, there mg agent such as alumina, charcoal or the like may be mentioned trichlorethylene, dichlorethylach th or by a combination of these processes or finally g fi ggfi iz zfi sggi igg purification by suitable filtration so that chlorohydmca'rbon. ma be carried out in em 10 in homolo ues of free from metal salts is obtained. The fact that ethgleneroxide, such s ig i g oxide dfbutyh 50 et yl oxide a form their hydroxides in a ene oxide or another alkylen oxide instead of i 011s solutions o metal salts is in Itself knownethylene oxide. Substitution products, such as The application of this reaction of ethylene oxide 1 pheny] ethylen id phendxypropene oxide or for purificati n 0 chloflnated ydrocarbons is. finally epichlorhydrin, are likewise suitable for I however, new and surprising. The most probable the process set forth. 4

What we claim is: 1. The process for purifying halogenated hydrocarbons oi the group consisting of halogenated methane, ethane, ethylene and acetylene which 6 are contaminated with metal chlorides, which comprises converting the metal salt by addition of a. compound containing the molecular configuration of the group consisting of alkylene oxides, phenylalkylene oxides, phenoxypropene oxide and epi-.

chlorhydrin with simultaneous action of water 5 into a non-volatile substance and separating the latter from the halogenated hydrocarbons.

2. The process for purifying halogenated hydrocarbons or the group consisting of halogenated methane; ethane, ethylene and acetylene which are contaminated with metal chlorides, which comprises adding ethylene oxide to the chlorinated hydrocarbon and distilling the latter in the presence of water.

3. The process for purifying halogenated hydrocarbqns of the group consisting of halogenated methane, ethane, ethylene and acetylene which FRIEDRICH PovENz, 15

ALFRED RIECHE. 

